1. Field of the Invention
This invention relates to method and apparatus for forming a channel to allow communication of fluids from one portion of a patient's body to another, and more particularly, to a device that can communicate blood between the left ventricle and coronary arteries or veins.
2. Description of the Related Art
Currently there exists a shunting concept that establishes a passage from the left ventricle directly to the coronary artery by the placement of a stent or hollow tube in a channel formed therethrough. Other designs also suggested that it might be possible to have a stent-less channel (see U.S. Pat. No. 5,662,124). Both designs have to deal with problems arising from the contraction and multidimensional movements of the heart wall in relation to the device. For a straight hollow tube the movement may create irritation between the tissue and the metal interface that may lead to a chronic inflammatory response, and maybe even to dislodgement of the tube. For a collapsible or expandable “wire” stent the constant movement can lead to fracture from cyclic fatigue (this has been documented in vivo humans —by Stent Medtronic). With respect to blood compatibility a solid tube presents maximum foreign surface to the blood of materials that are all relatively thrombogenic. While a wire or open stent design has less surface area exposed to blood, the profile of the stent in the flow field is less optimal and requires optimal placement.